Try to find the reason of dissatisfaction in your life.Then corelate with your profession.

Having this acceptance that you are doing a particular job for monetary benefits is purpose enough. The real question is why do you feel the urge of finding purpose? Is there a dissatisfaction with the way things are going overall? Usually it's only when things are off we tend to think more in these existential terms.

Firstly you need to analyse that you are pursuing this profession willingly or not. Finding yourself happy and contented or doing just for bread and butter because that can be the main reason of demotivation or lack of purpose many times despite having monetary benefits.  Procrastination and overthinking are symptoms of stress and anxiety. I would suggest you to consult a Psychologist and discuss it in detail.

Know what motivates you. Analyze your personal goals and find a company that supports them. Discover ways you can help make your company better. Assign personal performance metrics that really matter to you. Mentor, coach, and help others.